This little piggy will be fed penicillin and tetracycline before it goes to market.

这只小猪在上市前要喂青霉和四环。

In this case, the stool culture can be helpful in deciding which antibiotics would be most effective against the infecting strain, and may include tetracyclines, ciprofloxacin, ofloxacin, furazolidone, or trimethoprim-sulfamethoxazole.

粪便培养可以帮助确定哪种感染菌株最有效，可用的药物包括四环、环丙沙星、氧氟沙星、呋喃唑酮或甲氧苄啶-磺胺甲恶唑。

For example, tetracycline is common on mainland China's pig farms.

比如，中国大陆的养猪场普遍使用四环。

To keep it alive in the laboratory they use a compound called tetracycline.

为了在实验室中保持它的活， 他们使用了一种叫做四环的化合物。

There are exceptions though; expired antibiotics in the tetracycline family can actually cause kidney damage.

不过也有例外； 四环家族中过期的实际上会导致肾脏损害。

Unlike some antibiotics, tetracyclines can work against both gram-negative and gram-positive bacteria.

与某些不同，四环可以革兰氏阴性和革兰氏阳性细菌。

When we have antibiotics in our meat, we're not worried about getting like tetracycline from the chicken breast.

当我们肉类中有时，我们不必担心从鸡胸肉中摄入四环。

Tetracycline shuts off that gene and allows normal development.

四环关闭该基因并允许正常发育。

Microbiologists developed other tetracyclines during the 1950s, and many have since been used to treat a range of conditions, including acne, respiratory tract infections, stomach ulcers, chlamydia and Lyme disease.

微物学家在20世纪50年代开发了其他四环类药物，其中许多后来被用于治疗各种疾病，包括痤疮、呼吸道感染、胃溃疡、衣原体感染和莱姆病。

What we're worried about is the workers getting tetracycline, the chicken growing faster than it should, the meat being chewier and not as high quality.

我们担心的是工人接触到四环，鸡肉长过快，肉质变得粗糙且不够优质。

Almost half of all tetracyclines are used in animal husbandry.

几乎所有四环类药物中的一半都用于畜牧业。

Tetracyclines inhibit protein synthesis by entering the pathogen cell and preventing key molecules from binding to its ribosomes, tiny cellular structures or organelles.

四环通过进入病原体细胞，阻止关键分子与微小的细胞结构或细胞器——核糖体结合，从而抑制蛋白质合成。

Now, tetracyclines are no longer as effective for animals or humans.

如今，四环动物和人类的效果已大不如前。

The tetracyclines are another family of antibiotics that work as protein inhibitors.

四环是另一类，它们作为蛋白质抑制剂发挥作用。

1948. Benjamin Dugger discovers the first tetracycline antibiotic, which has its origin in a soil sample.

1948年， 本杰明·达格发现首种四环类，其源头可追溯至一份土壤样本。

Chlortetracycline was isolated from the bacteria, the first of the large family of tetracycline antibiotics.

金霉从这种细菌中分离出来，成为四环类大家族中的首位成员。